Strong-Wall Bracing Selector: Bridging the Gap between Engineered Design and Prescriptive Construction

Asking a structural engineer to design wall bracing under the IRC® can be like asking a French pastry chef to bake a cake using Betty Crocker’s Cookbook. The temptation is to toss out the prescriptive IRC recipe and design the house using ASCE 7 loads and the AWC SDPWS shear wall provisions per the IBC®. But if only a portion of the house needs to be engineered, there may be an easier option.

The prescriptive IRC states an IBC engineered design “is permitted for all buildings and structures and parts thereof” but the design must be “compatible with the performance of the conventional framed system.” But how exactly does an IRC braced wall panel perform? The code doesn’t come right out and tell us, but there are two bracing methods that are essentially shear walls masquerading as braced wall panels: Method ABW and Method BV-WSP. Backing into their allowable loads gives us the key to determining equivalence and eliminates the need to develop lateral forces.

But before you can bust out the slide rule and start crunching numbers, you need to figure out how much bracing the prescriptive code requires. We developed our Wall-Bracing-Length Calculator in 2010 to help designers do just that. And last month, we launched our Strong-Wall® Bracing Selector tool to make it easier to specify equivalent solutions for tricky situations.

Strong-Wall Bracing Selector
Strong-Wall Bracing Selector
Wall-Bracing-Length Calculator
Wall-Bracing-Length Calculator

You can export the required lengths (and project information) from the Wall-Bracing-Length Calculator directly into the Strong-Wall Bracing Selector or you can manually enter in the required lengths. The selector app will provide a list of Strong-Wall panels that have an equivalent length, evaluate their anchorage loads and return a list of pre-engineered anchor solutions for a variety of foundation types.

If you’re familiar with our Strong-Wall Prescriptive Design Guide (T-SWPDG10), the selector automates this 84-page document in just a few steps. One big upgrade is the ability to select a solution to meet the exact amount of bracing that is required. If you needed 2.8-ft. of wall bracing, you have to round up to the tabulated 4-ft. solutions if you are using the guide, but now you can select a wall solution that is equivalent to 2.8-ft., which might mean a smaller wall width or better anchor options. You also have the ability to save the selector file for later modifications, create a PDF of the job-specific output, or email the PDF directly from the program.

Strong-Wall Prescriptive Design Guide
Strong-Wall Prescriptive Design Guide

So next time you get asked to “design” some wall bracing, see if our Wall-Bracing-Length Calculator and Strong-Wall Bracing Selector might save you some time. There is a tutorial and a design example on the Bracing Selector web page, but it’s very easy to use so you may just want to dive right in. I should also point out that the Strong-Wall SB panels have not yet been implemented into the program, but bracing information for them is available on strongtie.com in posted letters for wind (L-L-SWSBWBRCE14), seismic (L-L-SWSBSBRCE14), and seismic with masonry veneer (L-L-SWSBVBRCE14).

Let us know what you think of this new tool in the comments below.

 

Shane Vilasineekul

Author: Shane Vilasineekul

When I started job searching my senior yearof college, I had several interviews with consulting firms before I saw a small flier, tacked to a hallway bulletin board, for interviews at a company called Simpson Strong-Tie. The name was new to me (wood design was not in the curriculum) and I hadn’t considered working for a manufacturing company, but I decided to schedule an interview (partly because The Simpsons was my favorite show at the time) and was fortunate to get the job.

At the time, one of my biggest concerns was that I would gain little structural engineering experience working for a “joist hanger” company. Well, it turned out that Simpson Strong-Tie was growing its line of concrete anchors and lateral force-resisting systems, and it was the Engineering Department’s philosophy that we had to be experts in all areas relating to these product lines in order to support them. Over the next several years I worked with, and was mentored by, some great engineers who helped me develop as a structural engineer and truly appreciate our profession. There are still times when I feel I haven’t paid my dues, but I am quickly reminded by my colleagues how lucky I am to have never had to worry about billable hours.

I graduated from Ohio State University in 1999 with a BS in Civil Engineering and hold a PE license in several states. For the last several years, I have been managing the engineering group out of the Simpson Strong-Tie Columbus, Ohio branch, which covers 24 states across the Midwest, Mid-Atlantic, and New England. The engineers at our branch focus on supporting our products through education, new product development, and by offering technical expertise.